Telangana SCERT Solution Class VIII (8) Math Chapter 1 Rational Numbers Exercise 1.1
(1) Name the property involved in the following examples
(i) 8/5 + 0 = 8/5 = 0 + 8/5
(ii) 2 (3/5 + 1/2) = 2 (3/5) + 2 (1/2)
(iii) 3/7 × 1 = 3/7 = 1 × 3/7
(iv) (-2/5) × 1 = -2/ = 1 × (-2/5)
(v) 2/5 + 1/5 = 1/3 + 2/5
(vi) 5/2 × 3/7 = 15/14
(vii) 7a + (-7a) = 0
(viii) x × 1/x = 1 (x ≠ 0)
(ix) (2×x) + (2×6) = 2 × (x + 6)
(2) Write the additive and the multiplicative inverses of the following.
(i) -3/5
(ii) 1
(iii) 0
(iv) 7/9
(v) -1
(3) Fill in the blanks
(i) (-1/17) + ( ____ ) = (-12/5) + (-1/17)
(ii) -2/3 + ____ = -2/3
(iii) 1 × ____ = 9/11
(iv) -12 + (5/6 + 6/7) = (-12 + 5/6) + ( ____ )
(v) ( ____ ) × (1/2 + 1/3) = (3/4 × 1/2) + (3/4 × ____)
(vi) -16/7 + _____ = -16/7
(4) Multiply 2/11 by the reciprocal of -5/14
(5) Which properties can be used in computing 2/5 × (5 × 7/6) + 1/3 × (3 × 4/11)
(6) Verify the following and write the property used
(5/4 + -1/2) + -3/2 = 5/4 + (-1/2 + -3/2)
(7) Evaluate 3/5 + 7/3 + (-2/5) + (-2/3) after rearrangement.
(8) Subtract
(i) 3/4 from 1/3
(ii) -32/13 from 2
(iii) -7 from -4/7
(9) What number should be added to -5/8 so as to get -3/2?
(10) The sum of two rational numbers is 8 If one of the numbers is -5/6 find the other.
(11) Is subtraction associative in rational numbers? Explain with an example.
(12) Verify that – (-x) = x for
(i) x = 2/15
(ii) x = -13/17
(13) Write –
(i) The set of numbers which do not have an additive identity
(ii) The rational number that does not have any reciprocal
(iii) The reciprocal of a negative rational number.
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